如何在 vb.net 中正确进行简单的数学百分比计算？
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How to do a simple maths percetange calculation correctly in vb.net?
提问by DreamTeK
Can this equation be reworked to a correctly formatted string?
这个方程可以改写为正确格式的字符串吗？
Dim Total = MyNumber / 100 * MyVAT
Produces error:
产生错误：
"Input string was not in a correct format"
回答by Tim Schmelter
You should really set Option Strictto on. Then this would never compile since MyNumberis a string(as you've commented).
你真的应该设置Option Strict为on. 然后这将永远不会编译，因为它MyNumber是一个字符串（正如您所评论的）。
You should first ensure that the input is numeric, for example with Decimal.TryParse:
您应该首先确保输入是数字，例如Decimal.TryParse：
Dim Total As Decimal
Dim num As Decimal
If Decimal.TryParse(MyNumber, num) Then
Total = num / 100 * MyVAT
End If
Now you can use Decimal.ToString(format)to convert it to a string with the desired format. For example(assuming you want two decimal places):
现在您可以使用Decimal.ToString(format)将其转换为具有所需格式的字符串。例如（假设您想要两位小数）：
Dim output As String = Total.ToString("N2")
回答by Mandeep Singh
try with this statement
试试这个说法
Dim Total = Val(MyNumber) / 100 * Val(MyVAT)
回答by ????
use like below
使用如下
Total.ToString("#")
More Detail:- http://msdn.microsoft.com/en-in/library/0c899ak8.aspx?cs-save-lang=1&cs-lang=vb#code-snippet-2
更多细节：- http://msdn.microsoft.com/en-in/library/0c899ak8.aspx?cs-save-lang=1&cs-lang=vb#code-snippet-2
